Q.1
A mineral is made of calcium, titanium and oxygen, Ca2+ ions located at corners, Ti4+ ions are at the bodycentre and O2- ions at face-centre of the unit cell, The molecular formula of the mineral is ..
  • a) CaTiO2
  • b) CaTi2O3
  • c) CaTiO3
  • d) XaTi2O4
Q.2
AB crystallises in body-centred cubic lattice with edge length 387pm. Distance between oppositely charged ions will be ..[ BHU 2009]
  • a) 200 pm
  • b) 250 pm
  • c) 300 pm
  • d) 335 pm
Q.3
8:8 coordination of CsCl is found to change into 6:6 coordination
  • a) on increasing the pressure
  • b) on increasing the temperature
  • c) on decreasing the pressure
  • d) on decreasing the temperature
Q.4
Fe3O4 is ferrimagnetic at room temperature but at 850K, it becomes
  • a) paramagnetic
  • b) diamagnetic
  • c) ferromagnetic
  • d) non-magnetic
Q.5
The number of atoms contained in one face-centred cubic unit cell of mono-atomic substance is
  • a) 1
  • b) 2
  • c) 3
  • d) 4
Q.6
Schottky defects occur mainly in electrovalent compounds where
  • a) positive ions and negative ions are of different size
  • b) positive ions and negative ions are of same size
  • c) positive ions are small and negative ions are big
  • d) positive ions are big and negative ions are small
Q.7
In Schottky defect ...
  • a) Some of lattice sites are vacant
  • b) an ion occupies interstitial position between lattice points
  • c) a lattice site is occupied by electron
  • d) the radius ratio r+/r-, is low
Q.8
The inter ionic distance for cesium chloride crystal will be
  • a) a
  • b) a/2
  • c) a(√3/2)
  • d) 2a√3
Q.9
In an NaCl crystal, each chloride ion is surrounded by ...
  • a) 6 sodium ions
  • b) 6 chloride ions
  • c) 8 sodium ions
  • d) 4 sodium ions
Q.10
Amorphous solids may be considered as ...
  • a) molecular solids
  • b) supercooled solids
  • c) supercooled liquids
  • d) covalnet network solids
Q.11
The anions (A) form hexagonal closed packing and atoms (M) occupy only two-third of octahedral voids in it; the general formula of the compound is ...
  • a) MA
  • b) A2
  • c) M2A3
  • d) M3A2
Q.12
First three nearest neighbor distance for primitive cubic unit cell will be ( edge length of unit cell = l)
  • a) l, l√2, 2l
  • b) l, l√2, l
  • c) l, l√2, l√3
  • d) l√3, l√2, l
Q.13
Close packing is maximum in the crystal lattice of
  • a) face-centred cubic
  • b) body-centred cubic
  • c) simple-centred cubic
  • d) none of these
Q.14
The unit cell of a binary compound of A and B metals has a ccp structure with A atoms occupying the corners and B atoms occupying the centres of each faces of the cubic unit cell. If during the crystallisation of this alloy, in the unit cell two A atoms are missed, the overall composition per unit cell is ...
  • a) A6B24
  • b) AB4
  • c) AB6
  • d) AB8
Q.15
Which defect causes decrease in the density of a crystal?
  • a) Schottky
  • b) Frenkel
  • c) F-centre
  • d) Interstitial
Q.16
The coordination number of a metal crystallizing in hexagonal close packing structure is
  • a) 4
  • b) 6
  • c) 8
  • d) 12
Q.17
The closest-packing sequence ABC ABC ... represents
  • a) primitive cubic packing
  • b) body-centred cubic packing
  • c) face-centred cubic packing
  • d) hexagonal packing
Q.18
A metallic crystal crystallizes into a lattice containing a sequence of layers AB AB AB. A packing of sphere leaves out voids in the lattice. What is the percentage of volume of this lattice in empty space?
  • a) 26%
  • b) 50%
  • c) 74%
  • d) None of these
Q.19
he number of crystal system known are ...
  • a) 4
  • b) 6
  • c) 7
  • d) 8
Q.20
In closed packed array of N spheres, the octahedral holes are
  • a) N/2
  • b) N
  • c) 2N
  • d) 4N
Q.21
A crystal lattice with alternate +ve and -ve ions has radius ratio 0.524, its coordination number is ...[ PMT 2002]
  • a) 3
  • b) 4
  • c) 6
  • d) 12
Q.22
If we mix a pentavalent impurity in a crystal lattice of germanium, what type of semiconductor formation will occur? ..[ CBSE 1996]
  • a) p-type semiconductor
  • b) n-type semiconductor
  • c) both types
  • d) none of these
Q.23
A metal crystallised with a body-centred cubic lattice. The edge of the unit cell is 240√3 pm. The diameter of the metal atom ion is ..[ AIPMT 2012]
  • a) 180 pm
  • b) 360 pm
  • c) 288 pm
  • d) 408 pm
Q.24
In a solid lattice, the cation has left a lattice site and is located at an interstitial position. the lattice defect is ...[ BHU 2008]
  • a) Interstitial defect
  • b) Vacancy defect
  • c) Frenkel defect
  • d) Schottky defect
Q.25
The packing fraction of the element that crystallises in Body -centred cubic unit cell arrangement is
  • a) π/6
  • b) π/2
  • c) π/4
  • d) π/3
Q.26
Tetragonal crystal system has the following unit cell dimensions ...[MPPMT 1993]
  • a) a=b=c and α=β=γ=90°
  • b) a=b≠c and α=β=γ=90°
  • c) a≠b≠c and α=β=γ=90°
  • d) a=b≠c and α=β=90°, γ=120°
Q.27
How many unit cells are there in 1 g of NaCl?
  • a) 6.023×1023
  • b) 2.57×1021
  • c) 2×6.023×1023
  • d) 4×6.023×1023
Q.28
In unit cell of NaCl lattice, there are ..
  • a) 3Na+ ions
  • b) 4NaCl units
  • c) 6Na+ ions
  • d) 6Cl- ions
Q.29
In hexagonal close packed (hcp) structure of spheres, the fraction of the volume occupied by the sphere is A. In a cubic closed packed structure, the fraction of the volume occupied is B. The relation between A and B is
  • a) A = B
  • b) A > B
  • c) A < B
  • d) both cannot be compared
Q.30
Which of following network solid is an exceptionally good conductor of electricity?
  • a) Si
  • b) SiC
  • c) Graphite
  • d) SiO2
0 h : 0 m : 1 s